Tube testing system



'June 3, 1941. H. P. MANLY TUBE TESTING SYSTEM 2 sheets-sheet 1 Filed March 22., 1940 FR Il EL 710A (UNTROL EL EME N 7J June 3, 1941. H. P, MANLY .2,244,495

TUBE TESTING SYSTEM Filed March 22, 1940 2 'sheets-sheet 2 jizz/@non patented June 3, 1941 TUBE TESTING SYSTEM Harold P. Manly, Wilmette, Ill., assigner to Charles P. Peirce, Evanston, Ill.

Application March 22, 1940, Serial No. 325,325

(Cl. Z50- 27) 9 Claims.

My invention relates, generally, to testing means l'or electric valves and the like, and it has particular relation to testing means wherein the various terminals of thermionic tubes may be selectively connected to a current source.

Thermionic tubes, classed under the broad term of electric valves, are of many difierent types. Each comprises a hermetically sealed bulb mounted on a base through which terminals for the internal elements project in the form of prongs or pins. These prong terminals may be in diiTerent arrangements, and it is ,usually impossible tc determine by visual inspec- :tion to which elements of the tube the terminals ,.belong. Thus, thermionic tubes of the nlament ,type in which the heated element acts as the .cathode commonly have two filament terminals arranged for connection to the two sides of a nlament current source. Insuch tubes the fila- ,ment element may terminate at any two of the pins or prongs on the base. With a base having eight pins, there are twenty-eight possible .-.dinerent filament terminal arrangements.

In tube testing equipment, it isdesirable to select the proper hase pins or terminals using a minimum number of sockets for the various types of tubes. It is also desirable to select and connect the proper base terminals to the opposite sides of a current source using a minimum number of switching means. Such testingr equipment should be simple in operation and construction, and arranged so as to make it impossible to short circuit the current source regardless of the comhinationof switch means that may be used.

rPhe object of my invention, generally stated, is to selectively connect the terminals of electric valves and the like having a plurality of terminals in different arrangements and unidentifable by Visual inspection to a current source.

An important object of my invention isv to test thermionic tubes using a minimum number of sockets of one type and a minimum number of switch units, so that any two terminalsmay be selected and connected to the leads of a current source without the possibility of operating a combination of the switch units that would short circuit the current source.

Another important objectof my invention is to selectively connect the terminals of 'a current source to the heater nlament terminals of thermionic tubes of the heater type having a separate cathode and a plurality of differently arranged terminals'while the cathode terminal is connected to one of the current'source termi"- nals using a minimum number of sockets `and switching units.

Other objects of my invention will, in part, be obvious, and in part appear hereinafter.

Accordingly, my invention is disclosed in the embodiments thereof shown in the accompanying drawings, and it comprises the features oi construction, combination of parts, and arrangement of elements which `will be exemplied in `nature and scope of my invention, reference may now behad to the following detailed description, taken in conjunction with the accompanying drawings, in which:

Figure 1 illustrates diagrammatically one embodiment of my invention for testing thermionic tubes;

Figure 2 illustrates diagrammatically another embodiment of my invention for testing thermionic tubes having a pair of heater nlament terminals and a separate cathode terminal; and

Figure 3 illustrates diagrammatically still another embodiment of my invention for also testing thermionic tubes having a pair of heater filament terminals and a separate cathode terminal.

Referring now to Figure 1 of the drawings, a thermionic tube testing system is indicated generally at 8, including a 6-pin socket 9. The socket 9 is provided with pin receptacles or terminals A, B, C, D, E, and F', as shown. A heater element or filament I0 is shown connected across `socket terminals B and D for heating a separate cathode II which is connected to socket terminal C. The secondary winding I2 of a transformer, shown generally at I3, has a primary winding I4 connected to a suitable alternating current source I5 andprovides a lament current source for testing purposes. The terminals or leads of the secondary winding I2 are indicated at I6 and I'I.

In order to selectively connect the socket terminals `B and D to the terminals I6 and IFI, double-pole double-throw switch units A', B', C', D', E', and F' are provided, as shown. Each of the switch units A', B', C', D', E', and F comprises upper and lower poles I8 and I9 respectively, including upper and lower movable contact members 20 and 2|. The contactmembers 20 and 2| may be mechanically interconnected for double-throw movement as indicated by the broken lines therebetween. When the upper movable contact members 25 are in their upper operative positions they engage stationary contact members 22, which are connected in parallel bers 2i are in their lower operative positions,l

they engage a setV of stationary contact members 2li which are connected in parallel circuit relationship with the current source terminal il.,

The intermediate Contact members 23 of switch unit A are connected to the current source ter minal le. The intermediate contact members 23 of switch B' are connected to the lower pole.

i9 of switch A', the intermediate contact members 23 of switch C" are connected tothe lower pole id of switch B', etc. The upper poles i8 of the switch units are connected to corresponding socket terminals A, B, C, D, E or F, as shown.

With the switch unit A' in its upper operative position, moving switch unit B to its lower operative position connects the socket terminal B to the terminal i6 through switch unit A' as shown. It will also be seen that with the switch unit B' in its lower operative position, al1 of the switch units to the right thereof are disconnected from the terminal I5. That is, when any one or" the switch units is in its lower operative position, all of the switch units to its right will be disconnected from the terminal I6. Now when the switch unit D' is moved to its lower operative position, with switch C" remaining in its upper operative position, the socket terminal Di is con-l nected to the terminal il' through switch units D', C' and B', as shown. Thus, the socket terminals B and D will be connected across the current source.

Regardless of what different combinations of operative positions the'switches may occupy, it is impossible to short circuit the secondary winding I2. The tube base pin or the socket terminal connected to the switch unit furthest to thel left and occupying its lower operative position is always connected to the terminal I6, while all base pins or socket terminals connected to switches to the right of this `left switch can only be connected to the terminal Il of the current source. It will be noted that when a filament terminal is in the socket terminal B connected to the switch unit B', which isA on the left of thevswitch unit C' to which the cathode terminal C is connected, it is possible to connect the filament Yterminals across the terminals I6 and Il while the cathode terminal may be connected to terminal I? by moving the switch C' to its lower operative position. However, if both of the terminals of lament lil were connected to any two of the socket terminals D, E, and F, it would be impossible to connect the lament terminals to the opposite current source terminals i6 and LIl when the switch C' is in its lower operative Vposition connecting the socket terminal C to the 'current source terminal i6. Instead, both of the nlament terminals would be connected to the terminal il and the heater filament Hl could not be energized.

In order to insure that the filament terminals may always Vbe connected to the opposite terminals of the current source no matter what base pin arrangement is involved, I have provided a tube testing system indicated generally at 3i! in Figure 2 of the drawings. Two complementary sockets 9-X and 9-Y are provided with socket terminals A, B, C, D, E, and F. The socket terminals of sockets 9-X and :l-Y are interconnected in reverse order. That is, A to F, F to A; B to E, Eto B; and, C to D, D to C. Now assuming a tube to be tested is inserted in socket 9-X having a separate cathode 3| connected to socket terminal B and a heater filament 32 connected to socket terminals at D and E. The socket terminals of socket 9--X are connected to the upper poles I8 of switch units A', B', C', D', E', and F', as in the tube test sys- Vtern 8 of Figure 1 of the drawings. With a view of testing the tube in socket B-X the switch units A',`B', C', D', E', and F' are operated as shown by the broken lines. That is, switches B', D', and E' are in their lower operative positions, while switches A', C', and F' remain in their upper operative positions. It will be seen that the socket terminal B to 'which the separate cathode 3l is connected will be connected to the current source terminal l' through switches B and A','while the lilament socket terminals D and E will be connected to the current source terminal il through switches D", C', and B', and switches E' and D', respectively. Since the lament terminals in socket terminals D and E are b'oth connected 'to current source terminal Il, the heater lament 32 cannot be energized. If the `tubebeing tested is now removed from the socket S-X and inserted into the socket 9-Y, and the switches A', B", C', D', E", and F' are operated to the positions shown in full lines, the cathode socke't'terminal B of socket 9-Y will now be connected tothe currentY source terminal I 'l through switches E', D' and C'. The

" filament socket terminal D of socket E-Y will now be connected to the current source terminal Il through switches C" .and B', and the lament socket terminal E of socket 9-Y will now be '2 connected to the current source terminal Iii u re 2 .of `the drawings, I have provided a test systemrindicated generally at 40 -in Figure 3 of the drawings. =Only one socket 9 is used. Assume that the tube to be Jtested is of .the same type as that discussed above inconnection with systemfSl of Figure `2 of the drawings. That is, a .tube having a separate cathode 3'! connecte'd to' socket terminal B, while the terminals 4of a heater filament -32 are connected' to socket terminals D a-nd E. Double-pole doublethrow switches -A', B', fC', D', E' and F' are interconnected between themselves andare connected to the rcurrent source terminals ligand ll, and to the currentlsource for control :of Athe tube elements, as vshown Vin Figures land 2 .of the drawings. However, 'the upper vswitch'gpoles I8 are connected to col-'responding socket terminals A, ,B, C, D, E, and F through a `six-pole double-throw switch indicated .generally-at lll, instead of -being connected directly -thereto, as in Figures y1 and 2. VThe switch 4|' comprises six sets of contacts 42 with a pole 43 for each set, as shown. Movable contact members 44 are provided which are mechanically interconnected for double-throw action as indicated by the broken line running therethrough. The dilerent sections` of the switch 4I may be designated as A", B", C", D", E, and F". The switch poles 43 are connected to corresponding socket terminals, as shown. The left hand contact member of each set of contacts 42 is connected to its corresponding pole i8 of the switches A', B', C', D', E', and F'. The right hand contact member of switch section A is connected to the switch pole I8 oi switch F. The right hand contact member of switch section B" is connected to the pole I3 of switch E. The right hand contact member of switch section C" is connected to the pole I3 of switch D', etc. To test the tube in socket 9 the movable contact members 44 ofswitch 4l may be moved to their right hand position, as shown, and switches B' C', and E may 'be thrown to their lower operative position, as shown. It will now be seen that socket terminal B, to which the separated cathode 3l is connected, is connected to the current source terminal Il through switch section B and switches E', D', and C'. Socket terminal D will be connected to the current source .terminal Il through switch section D and switches C and B. And, socket terminal E will be connected u to the current source terminal I6 through switch section E." and switches B' and A.

If when the movable Contact members lli of switch 4l are in the right hand position, the nlament terminals of a tube being tested are both connected to the current source terminal il, the movable contact members |34 may be then thrown to their left hand position allowing the lament terminals to be connected to the opposite terminals I6 and Il. This is equivalent to -changing from one socket to another in test system 3l) of Figure 2. A tube having any arrangement of lament terminals and a cathode terminal may thus be tested in the test system Ml by having the reversing switch :il in either its left hand or right f hand position, as the case may be.

In test systems 8, 3|] and 40 of Figures 1, 2 and 3 of the drawings respectively, sockets have been shown having six socket terminals. It will be understood that tubes may be tested having any number of base pins in sockets with a corresponding number of socket terminals. For each socket terminal a corresponding double-throw switch unit is provided. The electrical connections of each test system will be according to the principles of my invention as set 'forth above in connection with Figures 1, 2 and 3 of the drawings.

Since certain further changes may be made in the foregoing constructions, and different ernbodiments of my invention may be made without departing from the scope thereof, it is intended that all matter described hereinbefore or shown in the accompanying drawings shall be interpreted as illustrative and `not in a limiting sense.

I claim as my invention:

l. Testing means for electric valves and the like having a plurality of terminals in different arrangements comprising, in combination, means providing a plurality of terminals adapted to be engaged by the terminals of said valves and the like, switch means individual to each of said terminals of said terminal providing means for selectively connecting the same to the terminals of a current source, and circuit means interconnecting said switch means in such manner that no combination of positions thereof will cause short circuiting of .said current source.

2. Testing means for electric valves and the like having a plurality of terminals in different arrangements comprising, in combination, means providing a plurality of terminals adapted to be engaged by the terminals of said valves and the like, a double-pole double-throw switch unit individual to each of said terminals of said terminal providing means for selectively connecting the same to the terminals of a current source, and circuit means interconnecting said switch units in such manner that no combination of positions thereof will cause short circuiting of said current source. l

3. Testing means for selectively connecting the filament terminals of thermionic tubes having a plurality of terminals in different arrangements to the terminals of a lament current source comprising, in combination, a socket providing terminals for receiving the terminals of said thermionic tubes, a double-pole double-throw switch unit individual to each of said socket terminals for selectively connecting the same to the terminals of said filament current source,land circuit connections between said switch units so arranged that no combination of positions thereof will cause short circuiting oi' said filament current source.

4. Testing means for thermionic tubes of the heater type having a separate cathode and having a plurality of terminals in different arrangements by which the heater filaments may be selectively `connected to the terminals of a lament current `source comprising, in combination, a socket providing terminals for receiving the terminals 0i said thermionic tubes, a double-pole doublethrow switch unit individual to each of said socket `terminals for selectively connecting the same to the terminals of said iilament current source, and circuit connections between the switch units so arranged that no combination of positions thereof will cause short circuiting of said lament current source.

5. Testing means for thermionic tubes of the heater type having a separate cathode and having a plurality of terminals in different arrangements by which the heater lament =terminals may be selectively connected to the terminals of a nlament current source while the cathode terminal is connected to one of said lament current source terminals comprising, in combination, a first socket providing terminals for receiving the terminals of said thermionic tubes, a second socket providing terminals for receiving the terminals of said thermionic tubes, circuit connections interconnecting the terminals of said first and second sockets in reverse relationship, double-pole double-throw switch units individual to the socket terminals of one of said sockets, and circuit connections between said switch units so arranged that no combination of positions thereof will cause short circuiting of said lament current source.

6. Testing means for thermionic tubes of the heater type having a separate cathode and having a plurality of terminals in different arrangements by which the heater lilament terminals may be connected to the terminals of a lament current source while the cathode terminal is connected to one of said lament current source terminals comprising, in combination, a socket providing terminals for receiving the terminals of said thermionic tubes, double-pole double-throw switch units individual to each of said socket terminals, reversing switch means connected in circuit relationship between said switch units and said socket terminals whereby the connections therebetween may be reversed, and circuit connections between said switch units so arranged that no combination of positions thereof will cause short circuiting of said iilament current source.

7. Testing .means for electric valves and the like having terminals including filament terminals in different arrangements comprising, in combination, means providing a plurality of terminals adapted to be engaged by the terminals of an electric valve, a series of double-pole double-throw switches each individual to a terminal of said terminal means, circuit means interconnecting a iirst pole of each Switch to the terminal individual thereto, a pair of spaced apart contact members for each switch pole adapted to be individually engaged thereby, circuit means cominonly connecting corresponding contact members associated with said iirst switch poles to one terminal of a control voltage source, circuit means commonly connecting corresponding contact members associated with the second swi-tch poles to one terminal of a current source, circuit means interconnecting the remaining two contact members of the rst switch of said series to the opposite terminal of said current source, and circuit means interconnecting the second pole of each switch and the remaining two contact members of the next switch of said series.

8. Testing means for selectively connecting the filament terminals of thermionic tubes having a plurality of terminals in dierent arrangements to the oppositeterminals of a test current source comprising, in combination, aV socket providing terminals for receiving the terminals ci said ther'- mionic tubes,V a series of double-pole doublethrow switches each individual to a socket terminal, circuit means interconnecting a first pole of each switch to the socket terminal individual thereto, a pair of spaced apart contact members for each switch pole adapted to be individually engaged thereby, circuit means commonly connecting corresponding contact members assoclated with Said first switch pole to one terminal of a control Voltage source, circuit means commonly connecting corresponding contact mem-V bers associated with the second switch poles to one terminal of said test current source, circuit means interconnecting the remaining two contact members of the rst switch of said series to the opposite terminal of said test'current source, and circuit means interconnecting the second pole ci each switch and the remaining two contact members of the next switch of said series.

9. Testing means for thermionic tubes of the heater type having a separate cathode and having a plurality of terminals in different arrangements by which the heater filament terminals may be selectively connected to the terminals of a filament current source while the cathode terminal is connected to one of said filament current source terminals comprising, in combination, a rst socket providing terminals for receiving the terminals of said thermionic tubes, a second socket providing terminals for receiving the terminals or" said thermionic tubes, cir cuit connections interconnecting the terminals of said rst and second sockets in reverse relationship, a series of double-pole double-throw switches each individual to a socket terminal of one of said sockets, circuit means interconnecting a first pole of each switch to the socket terminal individual thereto, a pair of spaced apart Contact members for each switch pole adapted to be individually engaged thereby, circuit means commonly connecting corresponding contact members associated with said rst switch poles to one terminal of a control voltage source, circuit means commonly connecting corresponding contact member associated with the second switch poles to one terminal of said iilament current source, circuit means interconnecting the remaining two contact members of the rst switch of said series to the opposite terminal of said lament current source, and circuit means interconnecting the second pole of each switch and the remaining two contact members of the next switch of said series.

HAROLD P. MANLY. 

